The fate of Malaysia Airlines Flight 370 may no longer be a mystery: The Malaysian Prime Minister said Monday the flight went down somewhere in the southern Indian Ocean.

But for search crews, the announcement is just the beginning.

Their work now begins in earnest as teams step up their hunt for the plane and for clues about what exactly went wrong.

Ian MacDonald, a professor of oceanography at Florida State University, spoke to CNN's "The Lead With Jake Tapper" about how such a search would work.

"The first task is to look from the surface, to use listening devices as we heard, and then sonar and swath mapping techniques to try to locate anomalous debris fields, anomalous objects on the bottom and try to zero in based on that," he said.

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"But, ultimately, you have to go to the bottom of the ocean and search ... in a nested way, starting in a big area and honing in as the evidence begins to indicate where the debris might be."

Crews could use manned and unmanned vehicles in that next stage of the search.

One example of a manned craft is the Jiaolong -- one of the deepest diving research submersibles in the world. The Chinese took it to a depth of more four miles in 2012, MacDonald said, indicating that country's capabilities for deep ocean operations.

China has a particularly large stake in the search for Malaysia Airlines Flight 370: Its citizens made up about two-thirds of the passengers on the missing Boeing 777.

"I would not be at all surprised to see the Chinese take a very active role in trying to locate this aircraft, MacDonald said.

He also considered two types of unmanned vehicles -- autonomous underwater vehicles and remotely operated vehicles.

"Operators program a search pattern and then the vehicle is deployed," he said of the autonomous technology. "It dives to the bottom, usually operates about 100 feet or more off the bottom, and looks with sonar and other listening devices and tries to find the debris.

"So, it goes back and forth -- mowing the lawn -- and it can operate autonomously for periods of up to 24 hours, and then it's recovered and the operators download its data and try to see if they've located something," MacDonald said.

Photos:The search for MH370

Photos:The search for MH370

Two years after Malaysia Airlines Flight 370 went missing, a relative of one of the passengers burns incense in Beijing on March 8, 2016. Flight 370 vanished on March 8, 2014, as it flew from Kuala Lumpur, Malaysia, to Beijing. There were 239 people on board.

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Photos:The search for MH370

On July 29, police carry a piece of debris on Reunion Island, a French territory in the Indian Ocean. A week later, authorities confirmed that the debris was from the missing flight.

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Staff members with the Australian Transport Safety Bureau examine a piece of aircraft debris at their laboratory in Canberra, Australia, on July 20. The flap was found in June by residents on Pemba Island off the coast of Tanzania, and officials had said it was highly likely to have come from Flight 370. Experts at the Australian Transport Safety Bureau, which is heading up the search for the plane, confirmed that the part was indeed from the missing aircraft.

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Photos:The search for MH370

In late February, American tourist Blaine Gibson found a piece of plane debris off Mozambique, a discovery that renewed hope of solving the mystery of the missing flight. The piece measured 35 inches by 22 inches. A U.S. official said it was likely the wreckage came from a Boeing 777, which MH370 was.

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Relatives of the flight's passengers console each other outside the Malaysia Airlines office in Subang, Malaysia, on February 12, 2015. Protesters had demanded that the airline withdraw the statement that all 239 people aboard the plane were dead.

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A police officer watches a couple cry outside the airline's office building in Beijing after officials refused to meet with them on June 11, 2014. The couple's son was on the plane.

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Members of the media scramble to speak with Azharuddin Abdul Rahman, director general of Malaysia's Civil Aviation Department, at a hotel in Kuala Lumpur, Malaysia, on May 27, 2014. Data from communications between satellites and the missing flight was released the day before, more than two months after relatives of passengers said they requested it be made public.

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Operators aboard the Australian ship Ocean Shield move Bluefin-21, the U.S. Navy's autonomous underwater vehicle, into position to search for the jet on April 14, 2014.

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A member of the Royal New Zealand Air Force looks out of a window while searching for debris off the coast of western Australia on April 13, 2014.

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The HMS Echo, a vessel with the British Roya; Navy, moves through the waters of the southern Indian Ocean on April 12, 2014.

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A Royal Australian Air Force AP-3C Orion, on a mission to drop sonar buoys to assist in the search, flies past the Australian vessel Ocean Shield on April 9, 2014.

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A relative of a missing passenger cries at a vigil in Beijing on April 8, 2014.

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Australian Defense Force divers scan the water for debris in the southern Indian Ocean on April 7, 2014.

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A towed pinger locator is readied to be deployed off the deck of the Australian vessel Ocean Shield on April 7, 2014.

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A member of the Royal New Zealand Air Force looks at a flare in the Indian Ocean during search operations on April 4, 2014.

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On March 30, 2014, a woman in Kuala Lumpur prepares for an event in honor of those aboard Flight 370.

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The sole representative for the families of Flight 370 passengers leaves a conference at a Beijing hotel on March 28, 2014, after other relatives left en masse to protest the Malaysian government's response to their questions.

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A member of the Royal Australian Air Force is silhouetted against the southern Indian Ocean during the search for the missing jet on March 27, 2014.

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Flight Lt. Jayson Nichols looks at a map aboard a Royal Australian Air Force aircraft during a search on March 27, 2014.

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People in Kuala Lumpur light candles during a ceremony held for the missing flight's passengers on March 27, 2014.

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Malaysian Prime Minister Najib Razak, center, delivers a statement about the flight on March 24, 2014. Razak's announcement came after the airline sent a text message to relatives saying it "deeply regrets that we have to assume beyond any reasonable doubt that MH 370 has been lost and that none of those onboard survived."

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Grieving relatives of missing passengers leave a hotel in Beijing on March 24, 2014.

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A passenger views a weather map in the departures terminal of Kuala Lumpur International Airport on March 22, 2014.

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A Chinese satellite captured this image, released on March 22, 2014, of a floating object in the Indian Ocean, according to China's State Administration of Science. It was a possible lead in the search for the missing plane. Surveillance planes were looking for two objects spotted by satellite imagery in remote, treacherous waters more than 1,400 miles from the west coast of Australia.

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Satellite imagery provided by the Australian Maritime Safety Authority on March 20, 2014, showed debris in the southern Indian Ocean that could have been from Flight 370. The announcement by Australian officials raised hopes of a breakthrough in the frustrating search.

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Another satellite shot provided by the Australian Maritime Safety Authority shows possible debris from the flight.

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A distraught relative of a missing passenger breaks down while talking to reporters at Kuala Lumpur International Airport on March 19, 2014.

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On March 18, 2014, a relative of a missing passenger tells reporters in Beijing about a hunger strike to protest authorities' handling of information about the missing jet.

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U.S. Navy crew members assist in search-and-rescue operations in the Indian Ocean on March 16, 2014.

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Members of the Chinese navy continue search operations on March 13, 2014. After starting in the sea between Malaysia and Vietnam, the plane's last confirmed location, search efforts expanded west into the Indian Ocean.

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A Vietnamese military official looks out an aircraft window during search operations March 13, 2014.

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Malaysian air force members look for debris near Kuala Lumpur on March 13, 2014.

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Relatives of missing passengers wait for the latest news at a hotel in Beijing on March 12, 2014.

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A member of the Vietnamese air force checks a map while searching for the missing plane on March 11, 2014.

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A Vietnamese air force plane found traces of oil that authorities had suspected to be from the missing Malaysia Airlines plane, the Vietnamese government online newspaper reported on March 8, 2014. However, a sample from the slick showed it was bunker oil, typically used to power large cargo ships, Malaysia's state news agency, Bernama, reported on March 10, 2014.

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A U.S. Navy Seahawk helicopter lands aboard the USS Pinckney to change crews on March 9, 2014, before returning to search for the missing plane in the Gulf of Thailand.

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Buddhist monks at Kuala Lumpur International Airport offer a special prayer for the missing passengers on March 9, 2014.

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Members of a Chinese emergency response team board a rescue vessel at the port of Sanya in China's Hainan province on March 9, 2014.

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The rescue vessel sets out from Sanya in the South China Sea on March 9, 2014.

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Malaysian Prime Minister Najib Razak, center, arrives to meet family members of missing passengers at the reception center at Kuala Lumpur International Airport on March 8, 2014.

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A relative of two missing passengers reacts at their home in Kuala Lumpur on March 8, 2014.

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Pentagon spokesman Rear Adm. John Kirby said Monday that U.S. Navy equipment is en route to Australia to be used in case a debris field is found.

The Navy's Towed Pinger Locator 25 is able to locate flight recorders on downed aircraft to a maximum depth of 20,000 feet. The Bluefin-21 autonomous underwater vehicle has side-scanning sonar, which is useful in a debris field if there are underwater objects that need to be researched, Kirby said. It can operate at a depth of up to 14,700 feet.

Similar technology was used successfully in the hunt for Air France Flight 447, which disappeared in June 2009.

It took four searches over the course of nearly two years to locate the bulk of that wreckage and the majority of the 228 bodies in a mountain range deep in the Atlantic Ocean.

Once the wreckage has been located, MacDonald said crews could turn to using remotely operated vehicles.

They have an umbilical cord, which runs from the vehicle to the surface.

"The pilots can see what the ROV is seeing in real-time. They have mechanical arms, with claws and lifters that can untangle debris," he said. "The ROV technology would be crucial for manipulating the wreckage and untangling this mystery."